I've been to both USH and USF. I went to Shrek for the USH Annual Pass Preview and to the one here. (They let me into shrek with the Florida AP, but I still had to pay admission (although I went to guest services at USH and they did give me a 30% discount on admission-- I don't know if that's normal or not)
The show itself is identical, only the size and shape of the buildings are different. The preshow room in Hollywood is much wider than in Orlando. The mirror is on the far right, and the pigs are on the left in Hollywood. It's actually a lot easier to see all the preshow in Orlando.
This is the USH Preshow area... the mirror is to the right of the main screen. Unfortunately I don't have one of Orlando right now, but Orlando's is much more bunched together and the mirror is on the left.
The theater itself is larger in Hollywood, but not all that much. There is more open space at the edges of the room than in Orlando. That said, the wall effects seemed to work a lot better in Orlando.
The other difference is the Queue area, it lacks many of the signs that are in Orlando, except for one huge "Welcome to Duloc" -- Happiest totalitarian dictatorship on earth (well second happiest). This particular dig at Disney is missing here in Orlando, but there are plenty others to make up for that.
If you plan to get express passes to Shrek, get them early. They are going super fast right now.
